import std.container.rbtree;
import std.stdio;

class TClass
{
    int i;
}

void main()
{
    RedBlackTree!(TClass) list = new RedBlackTree!(TClass)();
    auto t = new TClass();
    list.insert(t);
    writeln("The rbtree length is ",list.length());
    list.removeKey(t);
    writeln("The rbtree length is ",list.length());
}
